Sediment sample retriever

ABSTRACT

A subaqueous sediment sample retriever head is affixed to the lower end of a continuous casing, which is positioned about a drill rod string and lowered onto a sampler tube, contiguous with the drill rod string. The retriever head houses in oppositely disposed cavities to a central bore, a pair of spools which store and actuate a flexible sealing slide respectively, and two pairs of spring actuated locking lugs which actuate simultaneously with the slide when the retriever head reaches the sampler tube bottom. A sleeve like follower device guides the retriever head onto the sampler tube and retains the sealing mechanism in an open position during mounting. The retriever head is advanced over the sampler by its own weight in conjunction with hydraulic jetting action.

United States Patent 1151 3,707,196 Verville 51 Dec. 26, 1972 [54]SEDIMENT SAMPLE RETRIEVER Primary Examiner-James A. Leppink [72]Inventor. William P. Vervllle, Concord, N.I-l. Assistant ExaminerRichard E Favreau [73] Assignee: The United States of America asAttorney-Chag'leS K, Wright, Jr. et a].

represented by the Secretary of the Army [57] ABSTRACT [22] Filed: July13, 1971 A subaqueous sediment sample retriever head is affixed to thelower end of a continuous casing, which is [21] Appl' l62107 positionedabout a drill rod string and lowered onto a sampler tube, contiguouswith the drill rod string. The 175/2 0, 175/243 retriever head houses inoppositely disposed cavities [51] Int. Cl ..E2lb 7/12, E2) 25/00 to acentral bore, a, pair of spools which store and 3c. Field of Searchtuate a flexible sealing slide respectively, and two pairs 242 of springactuated locking lugs which actuate simultaneously with the slide whenthe retriever head [56] References Cited reaches the sampler tubebottom. A sleeve like follower device guides the retriever head onto thesam- UNITED STATES PATENTS pler tube and retains the sealing mechanismin an 706,396 8/1902 Ebrenfeld ..17s/241 open position during mounting.The retriever head is 1,896,106 2/1933 Simmons.... ..175/243 X advancedover the sampler by its own weight in con- 2,915,284 12/1959 Ortloff..175/233 X junction with hydraulic jetting action. 3,301,336 1/1967Blount ..l75/5 3,409,094 11/1968 Kretschmer et al. ..175/242 10 Claims,10 Drawing Figures '1 i\ 0 7 A I 1* B r PATENTED B I912 3 707. 19s

SHEET 1 0F 3 INVENTOR. WILL/AM P. VE'RV/LLE ATTORNEY SEDIMENT SAMPLERETRIEVER The invention described herein may be manufactured and used byor for the Government for governmental purposes without the payment tome of any royalty thereon.

BACKGROUND OF THE INVENTION 1. Field of the Invention This inventionrelates to a subaqueous sediment sample retriever assembly, moreparticularly to a retriever head which is propelled by hydraulic jettingaction and employs a flexible sealing slide which is self-actuating whenthe retriever head reaches the bottom of the embedded sample tube.

It is well known in the art that laboratory tests to determine theengineering characteristics of soil samples require that such samplesapproximate as nearly as possible, their natural state. Obtainingundisturbed samples of very soft, unconsolidated sediments, orsaturated, cohesionless soils, or loose, compressible materials such asindustrial waste products is a very real and serious problem. For a soilsample to be suitable for laboratory testing, there must be nodisturbance of natural soil structure, no change in the water content orvoid ratio, and no change in the constituency or chemical composition.

bottom of said sampler tube. This is accomplished by housing a pair ofoppositely disposed spool assemblies in the retriever head. A firstspool stores a flexible slide which is retained in an open position bythe outer sampler tube wall as said retriever head advances downward,and a second actuating spool draws the slide across the sampler tubebore as soon as the slide is advanced below the bottom of said samplertube. Two pairs of oppositely disposed locking lugs, housed directlybelow the flexible slide, are actuated simultaneously with said slideproviding support therefor.

Accordingly, it is an object of this invention to provide aself-actuating sediment sample retriever head which will sever thebottom of the sample from its en- It is a further object of thisinvention to provide a sediment sample retriever assembly which utilizesDisturbance of the soil structure may occur either during or after theactual sampling operation. Experience has shown that the use of thinwall tube samplers reduces the disturbance of the soil structure duringthe insertion stage to a very narrow zone on the outer surface of thesample. Maximum possibility for disturbance occurs when the sample isdetached from the subsoil and during the subsequent withdrawal of thesampler tube from the bore hole. In addition to the force of gravity,suction on the sides and bottom of the sampler tube during withdrawalserves to further distort samples from their natural state.

2. Description of the Prior Art Various attempts have been made toobtain subaqueous soil samples in their undisturbed state. One of theearly devices consisted of flexible metal fringes mounted on a ringwhich fit into the interior of a core barrel near the cutting shoe.These flexible metal fingers allowed the core sample to enter but werebiased so that the sample was prevented from movement out of the barrel.The primary disadvantage of this type of device was that it restrictedthe core barrel entrance during corer penetration and it seriouslydisturbed and remodeled the core sample as the sample entered thebarrel.

Another sample retriever of more recent design is described in a patentissued to T. R. Kretschmer et al., U.S. Pat. No. 3,409,094. This sampleretriever is representative ofv those designs wherein the closure deviceis actuated upon withdrawal of the core retainer. This type of sampleclosure is not reliable, particularly in silt-like soils, in that propersealing is dependent upon sufficient downward sediment forces to actuatethe oppositely disposed pair of holding elements.

SUMMARY OF THE INVENTION The invention solves the aforementionedproblems by providing a retriever head assembly which will automaticallyseal the sampler tube as soon as it reaches the hydraulic jetting actionas its advancing means.

Another object of the invention is to develop a retriever assembly whichcan easily accommodate other drilling means so that this retrieverapparatus mayv be used to sample various silt-like to course sediments.

These and other objects, advantages, and novel features of the inventionwill become apparent from the following detailed description of theinvention when considered in conjunction with the accompanying drawingswherein:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side sectional view of theretriever head showing one pair of locking lugs;

FIG. 2 is an isolated, perspective view of the follower, showing thefluted waterways and locking lug recesses;

FIG. 3 is a partial sectional, perspective view of one locking lugassembly, showing the locking lug, cavity, and actuating spring;

FIG. 4 is a plan view of the upper section of the retriever head showingthe removable crank used to wind up the stainless steel slide;

FIG. 5 is a perspective view isolating the spool assemblies and showingthe slide in a half-open position;

FIG. 6 is the first in a series of sequential vertical sectional viewsshowing a sampler tube and attached drill rod embedded in a subwatersoil;

FIG. 7 shows the sample retriever head positioned about a drill rod withthe follower in place holding the slide and locking lugs open;

FIG. 8 is a view of the'retriever head in a depressed position about thesampler tube showing the follower in its stopped position;

FIG. 9 shows the retriever head at the bottom of the sampler tubewherein the slide and locking lugs have been activated to seal off thesampler tube; and

FIG. 10 is the final sequential view showing the sampler tube assemblybeing withdrawn from the subwater soil.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, moreparticularly to FIG. 1, a sediment sample retriever head 1 is shown insealing position about the lower end of a sampler tube 2.

The retriever head is constructed of steel and consists of two mainparts, an upper section 3 and a lower section 4.

The upper section 3 includes a threaded neck portion 5 to which isattached a flush joint casing 6 which extends upwardly to a controlstation, a smooth central bore 7, the diameter of which is approximately5% inch larger than the outside diameter of the thin wall tube samplerto be used, a plurality of outwardly, downwardly, and angularlyprojecting waterways 8 emanating from the central bore 7 and extendingto the outer edge of the retriever head, which together with thevertical, annular waterway 9 formed between the central bore 7 and thesampler tube 2, foster hydraulic jetting action generated from an abovewater head .of conventional design, and a pair of rectangular chambers10 and 11 disposed on opposite sides of the central bore 7 whichaccommodate a pair of communicating spool assemblies 12 and 13.

The housing for a first spool assembly 12 is a dimensioned rectangularinsert 14, the upper end of which is permanently affixed to acomplementing rectangular chamber 10 by machine bolts 15. A storagespool 16 is adapted for rotary motion within said chamber by means of apair of contiguous, oppositely disposed axle hubs 17 and 18 which fitinto corresponding slots 19 and 20 located in end portions 21 and 22 ofsaid rectangular insert, as shown in FIG. 4. t

The housing for a second spool assembly 13 is a similarly dimensionedrectangular insert 23 which is permanently affixed to a secondcomplementary rectangular chamber 11 by machine bolts 24. A torsionspring activated spool 25 is similarly adapted for rotary motion withinsaid chamber 11 by means of a pair of contiguous, oppositely disposedaxel hubs 26 and 27 which fit into corresponding slots 28 and 29 locatedin end'portions of said rectangular insert. A fixed end torsion spring30 is mounted within and activates said second spool 25 as shown by thecutaway portion of FIG. 4.

Directly communicating with both spool assemblies is a flexiblestainless steel slide 31, the width of which is made to exceed thesampler tube 2 diameter as shown in FIG. 4. The flexible slide 31 isaffixed to and stored on the storage spool 16 and two stainless steelwires 32 and 33 are attached to a positively tapered edge 34 of theslide and affixed to the spring activated spool 25.

When activated into sealing position, the flexible slide 31 is drawnthrough a longitudinal slot 35 in insert 14, across the central bore 9,and into mating engagement with a negatively tapered, longitudinalreceiving slot 36 in oppositely disposed insert 23. Receiving slot 36 isprovided with a pair of openings 37 and 3.8 through which stainlesssteel wires 32 and 33 pass.

An access hole 39 through the steel upper section leads, to axel hub 17which is equipped with an Allen type recess 40. A hand crank 41 which isequipped with a male type Allen wrench 42 is inserted in the access holeto engage the axe] hub 17 of the storage spool. Said storage spool canthus be rotated to wind up the attached flexible stainless steel slide31.

The lower section 4 of the retriever head is designed to fit the uppersection 3 and is joined to it with machine bolts 43. A plurality oflocking lugs 44 with means for actuating same are located around thecentral bore 7 in dimensioned cavities 45. The preferred embodimentshows two pairs of oppositely disposed locking lug assemblies locatednear the top of the lower section 4 with compression actuating springs47 as shown in FIG. 1.

When actuated, the oppositely disposed pairs of locking lugs 44 move outof their respective cavities 45, into sealing engagement with oneanother, providing support to the flexible slide 31 which is actuatedsimultaneously. Although the preferred embodiment shows a plurality oflocking lugs, it can readily be seen that a single locking lug member,extending across the central bore could also be utilized. I

The preferred embodiment of the instant invention utilizes hydraulicjetting action wherein a retriever head 1 is advanced over a samplertube by means of its own weight in conjunction with the advance sedimenterosion induced by the hydraulic jetting. There are instances, however,where the material to be sampled is too coarse grained or compact to beremoved solely by jetting action. In such instances, the invention canbe expanded upon to include a rotary drilling motion. By orienting thewaterways 8 in an angular fashion and equipping the lower surface 49 ofthe retriever head lower section 4 with cutting blades, the inventioncan be made to hydraulically drill a hard surface. Tungsten carbideinserts, either sweated into or welded to the receiver head, arerepresentative of suitable cutting blades.

As shown in FIG. 6, sampler tube 2 is contiguously affixed to the lowerend of a drill rod string 48, of lesser diameter, which emanates from anoverhead station. The annulus 50 formed between the outside diameter ofthe drill rod 48 and the inside diameter of the flush joint casing 6accommodates water passage from a surface pumping station to provide thewater pressure for the required jetting action.

Because of the diameter disparity between the sampler tube 2 and thedrill rod string 48, a follower device 51 as shown in FIG. -2 isrequired. Follower 51 is adapted to guide the retriever head 2 over thedrill rod string 48 onto the sampler tube 2 with means for retaining thelocking lugs 44 and flexible slide 31 in an open position. Morespecifically, follower 51 is a cylindrical sleeve of steel construction,having an inside diameter which is approximately Vs inch larger than theoutside diameter of the drill rod and an outside diameter which is thesame as that of the sampler tube being used. Said follower includes aplurality of downwardly extending fluted waterways 52, a plurality oflocking lug recesses 53 to retain said locking lugs in open position,and a beveled bottom 54 which engages and is retained by the taperedshoulder 55 of the sampler tube.

OPERATION OF SEDIMENT SAMPLE RETRIEVER A thin wall sampler tube 2 with aconnecting drill rod string 48 is pressed into a subaqueous soil from anoverhead station. Having inserted the sampler tube, a sample retrieverhead 1 with contiguous flush joint casing 6 and attached follower guide51 is positioned about the drill rod string and lowered onto theshoulder 55 of the embedded sampler tube. At this point, hydraulicjetting action is instituted from the overhead station, whereupon theretriever head disengages from the follower 51 which remains atop thesampler tube, and the retriever head advances downwardly about saidsampler tube propelled by its own weight and hydraulic jetting action asshown in FIG. 8. As the retriever head disengages from follower guide51, the flexible slide 31 and locking lugs 44 simultaneously engage theouter diameter of the sampler tube, thus remaining in open positionuntil the bottom of the sampler tube is reached. When retriever head 1reaches the sampler tube bottom as shown in FIG. 9, the flexible slideand supporting locking lugs, no longer retained by the outside diameterof the sampler tube, are simultaneously spring actuated thereby sealingoff the sampler tube bottom. At this point the hydraulic jetting actionis stopped and the sampler tube is withdrawn with the inclosed andundisturbed sample.

lclaim:

1. A sediment sample retriever assemblycomprising in combination:

a. a drill rod string and attached sampler tube;

b. a casing and attached retriever head adapted to be positioned aboutsaid drill rod string and lowered onto said sampler tube;

c. drilling means for advancing said retriever head in a downwarddirection about said sampler tube; and

d. a flexible slide, with housing and actuating means, for sealing off alower, open end of said sampler tube.

2. A sediment sampler retriever assembly according to claim 1 whereinsaid assembly further comprises a plurality of locking lugs, withactuating means, for supporting said flexible slide.

3. A sediment sample retriever assembly according to claim 2 whereinsaid assembly further comprises a follower device, adapted to guide saidretriever head about said drill rod string and onto said sampler tube,wherein said follower device further includes means for retaining saidlocking lugs and flexible slide in open, nonactuated positions.

4. A sediment sample retriever assembly according to claim 3 whereinsaid sampler tube is of greater diameter than said drill rod stringforming a shoulder on said sampler tube at the function of said drillrod string and said sampler tube providing a stop for said followerwhereby further travel of said retriever head beyond said juncturedisengages said locking lugs from to claim 1 wherein said drilling meanscompriseshydraulic jetting from an overhead pumping station which passesthrough a plurality of waterways located in said retriever head.

6. A sediment sample retriever head comprising in combination:

a. a central bore;

b. an upper section which houses a flexible slide, with actuating means,adapted to move between ;an open position and a closed, actuatedposition wherein said bore can be effectively sealed c. a lower sectionwhich houses a plurality otlockmg lugs, with actuating means, adapted tomove between an open position and a closed, actuated position, therebyproviding support for said flexible slide.

7. A sediment sample retriever head according to claim 6 wherein saidupper section of said retriever head includes a plurality of waterwaysemanating from the central bore and extending to an outer periphery ofsaid upper section.

8. A sediment sample retriever head according to claim 6 wherein saidupper section includes a pair of spool assemblies housed in chambersoppositely disposed to the central bore, a first spool serving as astorage spool about which said flexible slide is stored, and a secondactuating spool, communicating with said slide, which when actuateddraws the slide across said bore, thereby sealing said bore.

9. A sediment sample retriever head according to claim 8 wherein saidlower section includes two pairs of oppositely disposed, spring actuatedlocking lugs, housed in dimensioned cavities, oppositely disposed tosaid central bore.

10. A sediment sample retriever head according to claim 9 wherein saidflexible slide and locking lugs are retained in an open position by acylindrical sleeve like follower, the outside diameter of which isslightly less than that of said central bore.

1. A sediment sample retriever assembly comprising in combination: a. adrill rod string and attached sampler tube; b. a casing and attachedretriever head adapted to be positioned about said drill rod string andlowered onto said sampler tube; c. drilling means for advancing saidretriever head in a downward direction about said sampler tube; and d. aflexible slide, with housing and actuating means, for sealing off alower, open end of said sampler tube.
 2. A sediment sampler retrieverassembly according to claim 1 wherein said assembly further comprises aplurality of locking lugs, with actuating means, for supporting saidflexible slide.
 3. A sediment sample retriever assembly according toclaim 2 wherein said assembly further comprises a follower device,adapted to guide said retriever head about said drill rod string andonto said sampler tube, wherein said follower device further includesmeans for retaining said locking lugs and flexible slide in open,nonactuated positions.
 4. A sediment sample retriever assembly accordingto claim 3 wherein said sampler tube is of greater diameter than saiddrill rod string forming a shoulder on said sampler tube at the functionof said drill rod string and said sampler tube providing a stop for saidfollower whereby further travel of said retriever head beyond saidjuncture disengages said locking lugs from said follower, said lockinglugs being maintained in an open, nonactuated condition by said samplertube for the balance of travel of said retriever head on said samplertube and being actuated to support said flexible slide upon completionof travel beyond said sampler tube.
 5. A sediment sample retrieverassembly according to claim 1 wherein said drilling means compriseshydraulic jetting from an overhead pumping station which passes througha plurality of waterways located in said retriever head.
 6. A sedimentsample retriever head comprising in combination: a. a central bore; b.an upper section which houses a flexible slide, with actuating means,adapted to move between an open position and a closed, actuated positionwherein said bore can be effectively sealed; c. a lower section whichhouses a plurality of locking lugs, with actuating means, adapted tomove between an open position and a closed, actuated position, therebyproviding support for said flexible slide.
 7. A sediment sampleretriever head according to claim 6 wherein said upper section of saidretriever head includes a plurality of waterways emanating from thecentral bore and extending to an outer periphery of said upper section.8. A sediment sample retriever head according to claim 6 wherein saidupper section includes a pair of spool assemblies housed in chambersoppositely disposed to the central bore, a first spool serving as astorage spool about which said flexible slide is stored, and a secondactuating spool, communicating with said slide, which when actuateddraws the slide across said bore, thereby sealing said bore.
 9. Asediment sample retriever head according to claim 8 wherein said lowersection includes two pairs of oppositely disposed, spring actuatedlocking lugs, housed in dimensioned cavities, oppositely disposed tosaid central bore.
 10. A sediment sample retriever head according toclaim 9 wherein said flexible slide and locking lugs are retained in anopen position by a cylindrical sleeve like follower, the outsidediameter of which is slightly less than that of said central bore.